Generally, natural twists rightward or leftward in the lengthwise direction of band-like cloth irregularly occur when dyeing or washing the band-like cloth. It is necessary to continuously eliminate the twists when spreading the band-like cloth.
Therefore, the present applicant has designed and been manufacturing a twist eliminating machine represented by a machine disclosed by Japanese Patent Publication No. 19793 of 1979, and the outline thereof is described below.
That is, as shown in FIG. 4, 1 is a cloth guide wheel which is able to guide so as to cause band-like cloth w turned rope-like by narrowing the same to go upward and continuously go down.
2a and 2b are supporting axes juxtaposed to each other, 3a and 3b are spherical cloth contactors supported by each of the supporting axes 2a, 2b, and they function as a twist detecting device of the band-like cloth w.
4 is a cloth turning device which consists of a cylindrical rotating member 4 rotatably retained around a vertical axis and a motor 4b for causing the rotating member 4 to rotate.
When using the twist eliminating machine, the band-like cloth w turned rope-like by narrowing is upwardly inserted into an inner hole of the cylindrical rotating member 4 from its lower side, and continuously is caused to go down with the same applied to the cloth guide wheel 1. Thereafter, the band-like cloth is guided so as to be brought into contact with the arcuate contacting member r of a pair of cloth contactors, and a tensile force f1 is given to the point of the band-like cloth, wherein the band-like cloth is fed and supplied.
Thereby, the band-like cloth w will move with the wrinkle lines thereof being brought into contact with the arcuate contacting member r of the cloth contactors 3a, 3b. At this time, if any twist exists on the band-like cloth w, the wrinkle lines are inclined in a fixed direction, thereby causing an engaging force to be generated between the wrinkle lines and a number of longitudinal grooves m of the arcuate contacting member r. This engaging force causes the cloth contactors 3a, 3b to rotate in either left or right direction centering around the supporting axes 2a and 2b thereof, corresponding to the orientation of the twist of the band-like cloth w, against the resiliency of a spring (not illustrated).
Only when the rotation exceeds a specified value, this is electrically detected and the detection is outputted as twist information.
While the twist information is being outputted, the motor 4b begins to rotate in a particular direction corresponding to the orientation of the twist. In line with this rotation, the cloth turning device 4 is caused to rotate, and the band-like cloth w is accordingly rotated in a direction for eliminating the twist existing at the position of the cloth contactors 3a, 3b. Therefore, while the band-like cloth w is moving, the twist thereof can be kept less than a specified level.
The conventional twist detecting device has been widely utilized in the field of the corresponding industry, and the same is beneficial, too.
However, since in this kind of device, the thickness of band-like cloth w to be handled is determined by the relative position and size of a pair of cloth contactors 3a, 3b, the scope of the use is comparatively narrow. Especially, if the thickness is very narrow less than the allowance thereof, the band-like cloth w may be engaged between a pair of cloth contactors 3a, 3b, there may be cases where a desired operation can not be achieved.
If a tensile force acting on the band-like cloth w is too strong and the cloth w is excessively strongly brought into contact with the cloth contactors 3a, 3b even though the thickness of the band-like cloth w is within the allowance, a part of the band-like cloth w may be also engaged between a pair of cloth contactors 3a, 3b, thereby causing smooth operation not to be acquired. Therefore, in order to prevent this, it is necessary that another means is provided in addition thereto.